Information of artist and exhibitions

Hello, i'm doing a small research of photos and exhibition styles, and one of my major interests are whether artist print their photos on canvas in exhibition, and in order to show them, or they prefer to enlarge the photos and just stick them on the wall. its a work i do for the school of art, and its really interest me what is more preferable and usually done. i got some answers from this site: http://www.photogonia.com and they said that it change, and it depends on the artist needs and they gave me some numbers, if there are some professional photographers i will appreciate the info.